Sanding pad having a sealing element and a rib structure, and sanding machine

ABSTRACT

A sanding pad ( 40 ) for a sanding machine ( 15 ), including comprising a drive holder ( 49 ), situated on the machine side ( 41 ) of the sanding pad, to be fastened in a non-rotatable manner to a drive ( 26 ) of the sanding machine ( 15 ), such that the sanding pad ( 40 ) can be driven by the sanding machine in an in particular rotational and/or eccentric sanding motion that is suitable for sanding a workpiece (W); wherein the sanding pad has a machining side ( 42 ), which is opposite the machine side ( 41 ) and has a machining face ( 45 ) on which a sanding means ( 90 ) for abrasive machining of a workpiece (W) can be arranged so as to be fixed or removable using an adhesive layer ( 66 ); wherein inflow openings ( 48 ) for dust-laden dirty air (S) to flow in are situated in the machining face ( 45 ), and outflow openings ( 43 ) fluidically connected to the inflow openings via through-channels ( 59 ) are situated on the machine side ( 41 ).

The invention relates to a sanding pad for a sanding machine, comprisinga drive holder, situated on the machine side of the sanding pad, to befastened in a non-rotatable manner to a drive of the sanding machine,such that the sanding pad can be driven by the sanding machine in an inparticular rotational and/or eccentric sanding motion that is suitablefor sanding a workpiece (W); wherein the sanding pad comprises amachining side, which is opposite the machine side and has a machiningface on which a sanding means for abrasive machining of a workpiece (W)can be arranged so as to be fixed or removable using an adhesive layer;wherein inflow openings for dust-laden dirty air (S) to flow in aresituated in the machining face, and outflow openings fluidicallyconnected to the inflow openings via through-channels are situated onthe machine side; wherein the outflow openings are situated in a suctionzone within an annular sealing element that is situated on the machineside for sealingly contacting a counter-sealing element of the sandingmachine; wherein the sanding pad comprises a planar body which has asupporting wall provided for supporting the sanding means, whichsupporting wall is reinforced by a rib structure, the ribs of whichproject beyond the supporting wall towards the machine side; wherein theribs delimit cavities which are closed by the supporting wall withrespect to the machining side and are open with respect to the machineside. The invention also relates to a sanding machine which comprises asanding pad of this type.

Such a sanding pad is described, for example, in DE 10 2016 100 072 A1.In the case of the known sanding pad, the planar body is designed as asupporting body, wherein a soft pad is arranged on the lower side of thesame and is thus directed towards the machining side. The planar body isstiffened by a rib structure that extends around the drive holder. Asealing element in the form of a running surface extends annularlyaround this rib structure, on which a counter-sealing element, forexample a sealing collar or the like of the sanding machine can bear toform a seal. When the sanding pad rotates, the collar slides along thesealing element of the sanding pad and thus encloses a suction zone fromwhich dust-laden air can be extracted.

The concept of the known sanding pad provides that the ribs can only bearranged radially on the inside, close to the drive holder, while theplate-shaped sealing element or the running surface is provided radiallyon the outside. The stiffening concept is thus limited in the case ofthe known sanding pad.

A sanding pad known from U.S. Pat. No. 9,302,365 B2 has a planar body onwhich a sanding pad is arranged, wherein a row of through-flow openingsallows a flow through the sanding pad from its machining side to itsmachine side. A cover ring suitable for guiding a flow flowing throughthe through-flow openings is arranged on the machine side.

A sanding pad which has a cushion having a chamber structure is knownfrom DE 20 2013 010 480 U1. A support plate is arranged on the chamberstructure and covers the chamber structure.

DE 10 2010 012 007 A1 describes a sanding plate having a base plate thathas a tool holder for driving a sanding machine, and a cushion parthaving air channels on the lower side of the base plate.

It is therefore the object of the present invention to provide animproved sanding pad and a sanding machine equipped therewith.

To achieve the object, it is provided in a sanding pad of the typementioned at the outset that the sealing element covers at least some ofthe cavities toward the machine side.

A basic concept of the sanding pad is that the rib structure is alsopresent in the region of the sealing element, for example the runningsurface for the counter-sealing element of the sanding machine, whereingaps between the ribs are covered by the sealing element. Thus, theplanar body and ultimately also the sanding pad are also reinforced bythe rib structure in the region of the sealing element or in the radialdistance of the sealing element to the drive holder. Nevertheless, thesealing element is located there.

Cavities of the planar body that are closed or covered by the sealingelement are, in particular, such cavities that are closed to theradially outer edge region of the planar body by the material of theplanar body.

The planar body preferably forms a hard component of the sanding padthat stiffens the sanding pad.

The planar body is preferably not made of a foamed material and/or madeof foam.

The planar body is preferably made of a hard plastic or rigid plastic ormetal.

The planar body is advantageously harder and/or more rigid in relationto a cover body, for example a sanding pad, arranged on the machiningside.

The rib structure is preferably integral with the supporting wall.However, it is also possible for the rib structure to be adhesivelybonded, overmolded or cast onto the supporting wall or the like.

It is advantageous if the sanding pad is manufactured in such a way thatthe sealing element forms a first component and the supporting wall,which has the rib structure, forms a second component of the sandingpad, which are or will be connected to one another.

Therefore, the rib structure already present on the supporting wall isat least partially covered by the sealing element in the course of theproduction of the sanding pad.

It is advantageous if the planar body has further ribs on a radiallyouter edge region with respect to the drive holder, in particular ribsof the type that extend in a star shape or radiate from a center of theplanar body or sanding pad. Such ribs can have a stiffening function,for example. It is also possible for the ribs to form flow channels.Recesses are present between these ribs, which are advantageously notcovered by the sealing element. The radially outer edge region of theplanar body is advantageously not covered by the sealing element.

The sealing element can be plate-like, for example. However, it is alsopossible for the sealing element to contain a sealing collar or a partof a sealing collar. Therefore, the sealing element or thecounter-sealing element or both can be designed as a collar or anotherflexible sealing element.

During operation of the sanding machine, the sealing element and thecounter-sealing element bear against one another in a sealing fit, sothat the suction zone is housed or enclosed by the sealing element andthe counter-sealing element.

The sealing element which covers the cavities on the machine side ispreferably the only sealing element for the sealing contact of the or ofa counter-sealing element of the sanding machine.

The planar body and/or the sealing element are preferably essentiallyrigid, in particular when arranged on one another.

The sealing element preferably has a sealing surface for contacting thecounter-sealing element, which is designed as a flat surface or planarsurface. The sealing surface and the machining surface are preferablyparallel to each other.

The sealing element preferably comprises a ring body and/or plate-shapedor wall-like body.

The planar body and/or the sealing element advantageously consist ofmetal and/or a thermosetting plastic. The planar body and/or the sealingelement can consist of a fiber-reinforced material, for example, onecontaining glass fibers and/or carbon fiber-reinforced plastic.

The planar body is preferably designed on the machine side in such a waythat, without the sealing element at least partially covering thecavities, it has no sealing surface, in particular no sealing surfaceextending annularly around the drive holder, for sealing contact withthe or a counter-sealing element of the sanding machine. In principle,however, it is possible for the planar body to have, in addition to thesealing element covering the cavities, at least one additional sealingsurface or sealing contour, in particular extending annularly around thedrive holder, for sealing contact with a counter-sealing element of thesanding machine.

Both the sealing element and the counter-sealing element can be hardcomponents or soft components or both. In particular, it is advantageousif the sealing element is plate-shaped or flat, i.e., the componentlocated on the sanding pad has a plate-like or web-like shape. Thecounter-sealing element is preferably designed as a seal collar orsealing collar, which is arranged, for example, on the tool holder ofthe sanding machine, which can be brought into engagement with the driveholder of the sanding pad. For example, the tool holder of the sandingmachine is located in particular centrally within the counter-sealingelement and is annularly enclosed thereby. Of course, this configurationis also advantageous in the sanding pad, i.e., the drive holder islocated centrally in the region of the sealing element or in its center.

The sealing element and the planar body can be integral. For example,the sealing element is extruded onto the planar body or integrallyproduced, for example by an injection molding process.

A preferred concept provides that the planar body and the sealingelement are separate components that are, however, fixedly connected toone another. The fixed connection can be a non-detachable connection,for example a welded bond, adhesive bond, or the like. The fixedconnection can also be a detachable connection, for example a latchingconnection, clamp connection, form-fitting connection, adhesive bondwith a detachable adhesive, or the like. However, the sealing element isarranged in a stationary manner on the planar body during operation ofthe sanding pad or for operation of the sanding pad on the planar body.

At least one cavity of the planar body that is covered by the sealingelement of the sanding pad on the machine side is advantageously ademolding cavity that is formed by removing a casting core from thecavity. The planar body is produced, for example, by means of a die anda core. The die ultimately defines the formation of the supporting wall,while the core is needed to form the rib structure. The casting cavity,in which the planar body is formed during casting or injection molding,is provided between the die and the core. If the core is removed fromthe matrix, i.e., the planar body is removed, so to speak, the cavitiesbetween the ribs of the rib structure are created.

It is advantageously provided that the sealing element covers and/ortightly closes all the cavities of the planar body within the suctionzone and/or on a planar flat side of the planar body between the driveholder and an edge region of the planar body. For example, the planarbody has further ribs on the outside or radially on the outside withrespect to the drive holder or the sealing element, which, however, arenot covered or overlapped by the sealing element. The edge regionpreferably has a conical or sloping profile. The edge region preferablyrises from the outer edge of the planar body to its region at which thesealing element is arranged.

It is possible that the sealing element, except for the outflowopenings, covers all cavities or at least a large part of the cavitiesof the planar body, in particular closes them tightly. It isparticularly advantageous if the sealing element, except for the outflowopenings, covers or tightly closes all cavities of the planar body thatare not open radially outwards with respect to the drive holder of theplanar body or sanding pad.

It is particularly advantageous if the sealing element closes at leastone, preferably multiple, or all cavities completely and/or tightly.

A preferred concept provides that the sealing element, except for theoutflow openings, tightly closes at least part of the cavities,preferably all cavities or a large number of cavities, so that a volumelocated in the respective cavity is closed or enclosed in a dust-tightmanner

Those cavities of the planar body which are closed by the sealingelement are preferably completely closed by the sealing element. Such aclosed cavity is closed, for example, by the rib structure, wherein ribsof the rib structure form peripheral walls of the cavity, and onopposite sides by the supporting wall and the sealing element. Thesealing element and the supporting wall are connected to the ribsforming the peripheral walls in such a way that the cavity is completelyclosed.

It is preferably provided that the sealing element covers and/or tightlycloses at least one, multiple, or all of the cavities provided anddesigned to form one or more through channels and/or at least one or allthrough channels. It is possible that cavities distant from the throughchannels are covered by the sealing element, but are not completelytightly closed. A cavity covered by the sealing element that is nottightly closed, for example by welding or adhesive bonding, is alsoprotected against the penetration of dust.

Therefore, cavities are initially still present in the raw planar body,so to speak, but these are covered or closed by the sealing element. Thecavity is delimited on first sides, for example two, three, or foursides, for example by the ribs and the supporting wall, and the sealingelement closes the at least one second side, for example a fourth,fifth, or sixth side. It is therefore advantageous if the sealingelement, the supporting wall, and the ribs completely surround orenclose a volume in one or more cavities. No dust can therefore get intothe respective cavity when the sanding pad is in operation. As a result,the mechanical properties, for example balancing or synchronization ofthe sanding pad, do not change or are at least not changed by dust thatcould otherwise settle in the cavity.

It is preferred if the sealing element rests flatly on the end faces ofthe ribs of the rib structure facing toward the sealing element. Thismakes it possible, for example, to enclose volumes in a respectivecavity.

It is also advantageous if the sealing element is connected to theplanar body, for example to the ribs, in particular to their end faces,by means of a weld, for example a thermal weld, an ultrasonic weld, orthe like. However, additionally or alternatively to a weld, an adhesivebond can also be provided. Therefore, a permanent connection of sealingelement and planar body is advantageous.

To produce a weld, in particular a thermal weld, it is advantageous ifso-called welding tips or welding projections are provided. It isadvantageous, for example, if the sealing element and/or the planar bodyhave at least one welding projection, for example a welding tip, weldingrib, or the like, for welding to the respective other component ofplanar body and sealing element or are connected to one another by meansof such a welding projection. The welding projection can be configuredas a narrow ridge, for example. The at least one welding projection canbe a so-called energy director, for example. In the case of thermalwelding, for example ultrasonic welding, the welding projection meltsand thus ensures that planar body and sealing element are welded.

It is possible that the at least one welding projection has an elongatedshape. However, the at least one welding projection can also, forexample, comprise or be formed by an arrangement of multiple weldingspots or punctiform welding projections.

The at least one welding projection or a welded connection formed bymeans of the welding projection is, for example, designed like a frameor forms a frame. The at least one welding projection or a weldedconnection formed by means of the welding projection extends, forexample, around an outflow opening of the planar body in such a way thatthe outflow opening is sealed off from the surroundings when the atleast one welding projection or a welded connection formed by means ofthe welding projection connects the sealing element tightly to theplanar body in the surroundings of the outflow opening. As a result, forexample, no dust-laden air from the region of the outflow opening canget between the sealing element and the planar body.

The planar body and the sealing element are advantageously supported ina form-fitting manner on one another in a direction of force parallel tothe machining surface or geometric plane of the machining surface. Forexample, form-fitting contours of planar body and sealing element bearagainst one another. The form-fitting contours or form-fitting surfacescan include, for example, form-fitting projections and form-fittingreceptacles on one part each of planar body and sealing element. Theform-fitting support can, for example, support a torque that occursbetween planar body and sealing element during operation using thesanding machine. Such a torque results, for example, due to friction ofthe counter-sealing element on the sealing element and/or in the case ofsanding contact of the machining surface on a workpiece, in each casewhen the sanding pad is driven by the sanding machine.

At this point it should be mentioned that the sanding machine canreadily be a rotary sanding machine, i.e., the sanding pad is designedand provided for rotational, abrasive, or sanding machining of aworkpiece. However, it is also possible for the sanding pad to beconfigured as an eccentric sanding pad and the sanding machine as aneccentric sanding machine. It is readily possible that various operatingmodes are settable, for example by setting the sanding machine between arotation principle, an eccentric drive principle, or a hypercycloidalrotation drive principle, i.e., to an eccentric rotation operation.

It is preferred if the sealing element, for example by means of clampingmeans and/or latching means and/or a detachable adhesive bond, isdetachably arranged on the planar body. Although the sealing element isa separate component per se from the planar body, it is detachablyconnected to the planar body. Thus, for example, when the sealingelement or the planar body is worn, the respective worn component caneasily be replaced.

The sealing element and the planar body are expediently connected to oneanother in a form-fitting manner by at least one pairing of aform-fitting projection and a form-fitting receptacle, wherein theform-fitting projection and the form-fitting receptacle extendtransversely, for example perpendicularly, to the machining surface andinterlock. The at least one form-fitting projection is, for example, aform-fitting pin and the at least one form-fitting receptacle is aform-fitting pin receptacle. Of course, the form-fitting projection canalso have a wall-like configuration. The form-fitting projection can besupported, for example, on a rib of the rib structure. A form-fittingreceptacle is then formed between the ribs. It is possible that arespective form-fitting projection is supported only in one direction offorce on a wall of a form-fitting receptacle, for example on a rib ofthe rib structure. At least one pairing or an arrangement of multiplepairs of form-fitting projections and form-fitting receptacles can alsobe used as an assembly aid or temporary holder, for example until a weldor adhesive bond is produced between the sealing element and the planarbody.

A latching pin or latching projection is expediently provided as atleast one form-fitting projection. The at least one form-fittingreceptacle expediently includes a latching receptacle.

The at least one form-fitting projection can also be a plug projectionand the at least one form-fitting receptacle can be a plug receptacle.The plug projection is pluggable into the plug receptacle along a plugaxis. Of course, a plug receptacle can be designed as a latching plugreceptacle and a plug projection can be designed as a latching plugprojection.

The plug receptacle and the plug projection expediently have reargripping surfaces which extend transversely to the plug axis and impedeor prevent removal of the plug projection from the plug receptacle. Therear gripping surfaces can be aligned, for example, obliquely to theplug axis or at right angles to the plug axis. It is possible that therear gripping surfaces are normally at a distance from one another, inparticular when the sealing element is in any case subjected to a forcein the direction of the planar body, in particular by thecounter-sealing element. However, it is preferred if the rear grippingsurfaces bear against one another, so that the sealing element is alsoheld fixedly on the planar body in the direction of the plug axis.

The plug projection expediently has at least two plug segments,preferably three or four plug segments, which can be moved relative toone another transversely to the plug axis. When the plug projection isplugged into the plug receptacle, the plug segments are displaceabletowards one another and/or movable away from each other. For example,the plug segments can initially be displaced towards one another in theplug axis direction when they are plugged in, until there is free spacethat allows the plug segments to move away from one another again. Theabove-mentioned rear gripping surfaces are provided on the free space,for example. The plug segments are formed, for example, in that the plugprojection has a slot that extends in the direction of the plug axis andpenetrates a plane in which the plug axis is located.

It is preferred if the sealing element has at least one support contour,for example a support receptacle and/or a support rib projecting infront of the sealing element, which is provided and configured forlateral contact on a rib delimiting a cavity. The support contour canalso be, for example, a welding projection or can be formed thereby. Asa result, the sealing element and the planar body are supported on oneanother in a direction of force parallel to the machining surface. Inprinciple, however, it is also possible that the planar body has asupport contour, in particular a support rib, provided and configuredfor engagement with a counter-support contour of the sealing element,for example for engagement in a support receptacle, groove, or the likeon the sealing element.

It is preferred if the sealing element has two spaced-apart supportcontours, for example two spaced-apart support ribs or inner sides of aform-fitting receptacle, in particular a receptacle groove, which areintended for contact on opposing ribs delimiting a cavity or, forexample in the form of a receptacle groove, delimit a receptacle for theengagement of a rib. Thus, the sealing element and the planar body aresupported on one another in opposite directions of force parallel to themachining surface.

It is furthermore preferred if the at least one support contour has atleast two support contours extending at an angle to one another, forexample support ribs, for support on ribs which are at an angle to oneanother. As a result, the sealing element and the planar body aresupported on one another in directions of force at an angle to oneanother parallel to the machining surface.

An advantageous embodiment can provide that the at least one supportcontour comprises a support frame for lateral contact on an innercircumference of a cavity delimited by ribs, for example three or fouror five ribs. The ribs and legs of the support frame extend at an angleto one another, for example, in the shape of a triangle, a square, atrapezoid, or the like.

The at least one support contour can preferably form or comprise awelding projection for thermal welding, for example ultrasonic welding,of the sealing element to the planar body. However, it is also possiblethat the at least one support contour, for example, only ensures aform-fitting hold of the sealing element on the planar body and/orrepresents a support contour which is provided and configured for theadhesive bonding of sealing element and planar body.

In principle, it is possible that the sealing element covers allcavities on the machine side that are located within the suction space.Cavities located outside of the suction space can also be covered by thesealing element. It is possible here that all cavities located outsideof the suction chamber are covered by the sealing element.

However, a design is preferred, i.e., that the sanding pad has a coverelement which covers at least part of the cavities on the machine side.Thus, both the sealing element and the cover element can each covercavities on the machine side. A sandwiched arrangement is also possible,i.e., both the cover element and the sealing element are arranged abovea respective cavity. It is also possible that the sealing element coversat least part of the cavities with the interposition of the coverelement, which it would also cover without cover element.

The cover element is preferably plate-shaped. The cover element ispreferably configured as a ring body.

It is also possible that the sealing element and the cover element areintegrally or fixedly connected to one another. Furthermore, it ispossible that the sealing element comprises or forms the cover element.

The cover element is preferably held fixedly on the planar body. Forexample, the cover element is held on the planar body in a form-fittingmanner and/or by means of the sealing element and/or by means of anadhesive bond, in particular a detachable adhesive bond, and/or a weld.The sealing element can thus form a holding element for the coverelement, so to speak. It is also readily possible for the sealingelement to be held on the planar body by means of the cover element, forexample in a form-fitting manner For example, a part of the sealingelement can engage in a gap between cover element and planar body andcan thus be held by the cover element on the planar body.

The cover element advantageously has openings that can be provided formultiple purposes, for example for form-fitting elements, using whichthe sealing element and the planar body are fixed on one another in aform-fitting manner, for engaging holding contours of the sealingelement, i.e., for example holding projections which are arranged on thesealing element and engage in the openings. However, the openings canalso be provided for dirty air to flow through or for the drive holder.The openings can preferably be passage openings.

However, it is also possible for the openings to be only recesses orindentations, for example for engaging holding contours of the sealingelement. Passage openings are not absolutely necessary at these points.

The sealing element preferably has holding projections for holding thecover element on the planar body. The holding projections preferablyextend in a plane parallel to the machining surface. The holdingprojections can comprise hook projections, the hook sections of whichengage in the cover element, for example in one of the above-mentionedopenings, which are configured as passage openings or recesses. Theholding projections can be or comprise holding projections whichprotrude radially outwards, i.e., away from the drive holder, butpreferably in the direction of the drive holder. In particular in thedirection of the drive holder, namely in the suction zone, it isadvantageous if additional holding projections hold the cover element onthe planar body. The holding projections can extend up to the driveholder.

The sealing element and/or the cover element preferably completely oressentially covers cavities of the planar body in the region of thesuction zone. It is advantageously provided that only outflow openingsfor the dirty air in the suction zone and/or the drive holder are notcovered by the sealing element and/or the cover element.

For example, the sealing element and the cover element are concentricand/or annular. Both the sealing element and the cover element canextend annularly around the drive holder. Circular rings are readilypossible here.

If the sanding pad has a shape other than circular, for example atriangular or rectangular shape, it is advantageous if the sealingelement and/or the cover element have a similar basic geometric contouras the planar body or the sanding pad. Although the above-mentionedannular shape of the sealing element and the cover element can be acircular annular shape, it can also be, for example, a triangularannular shape or a rectangular annular shape.

The sealing element and/or the cover element expediently have an outerperipheral contour which correlates with the outer peripheral contour ofthe planar body or sanding pad, for example, a round or circular annularouter peripheral contour, a triangular outer peripheral contour, or arectangular outer peripheral contour.

The cover element is preferably fixed on the planar body by the sealingelement in a rotationally-fixed manner with respect to an axis ofrotation around which the planar body rotates during operation of thesanding machine. Form-fitting contours, using which the sealing elementand the planar body are engaged with one another, preferably engage in aform-fitting manner in form-fitting receptacles or form-fitting contoursof the cover element.

The sealing element and/or a cover element that at least partiallycovers the cavities of the planar body, for example the above-mentionedcover element, can be plate-like or wall-like.

It is possible that the sealing element has a higher mechanical loadcapacity and/or wall thickness than the cover element. For example, thecover element can consist of a film-like material or a material having athin wall thickness, while the sealing element, which is at leastfrictionally loaded during operation by the counter-sealing element ofthe sanding machine, has a higher rigidity or strength than the coverelement. For example, a step is provided between the sealing element andthe cover element. The step is formed, for example, in that the sealingelement has a greater material thickness than the cover element.

The sealing element and/or the or a cover element at least partiallycovering the cavities of the planar body, for example both together,cover, except for the outflow openings for the dirty air outside and/orwithin the suction zone, all cavities of the planar body on the machineside, which are closed with respect to an outer circumference of theplanar body between the machine side and the machining side. Forexample, further cavities can be provided radially on the outside or atthe edge of the planar body, which are not closed by the cover elementor sealing element. For example, ribs of the rib structure are open atthe edge or towards the outer edge of the sanding pad and are notcovered there by the sealing element or cover element.

At least a part of the ribs of the planar body extend radially orradiating away from the drive holder to an edge region of the sandingpad. Of course, transverse ribs or transverse reinforcements can beprovided between these ribs.

A part of the ribs of the planar body preferably define a common supportplane or support surface in which the ribs support the sealing elementand/or the cover element. The support plane is, so to speak, anenveloping or common plane in which the ribs of the planar body form asupport plane, so to speak. The support plane can be a flat surface orflat plane. It is advantageous if all ribs or cavities of the planarbody in the region of the support plane are covered and/or closed by thesealing element and/or the cover element.

The supporting wall can be a substantially closed supporting wall, onwhich the inflow openings are provided, however. However, it is alsopossible that the supporting wall has recesses and indentations on themachining side, so that a type of rib structure is formed, for example.The supporting wall of the planar body has, for example, recesses on themachining side to form the inflow opening and/or for providing at leastpartial sections of the through channels. The recesses extend, forexample, radially from an outer circumference of the sanding pad towardthe drive holder and/or toward the outflow openings located adjacent tothe drive holder.

The machining surface of the sanding pad can be provided directly by thesupporting wall. For example, an adhesive layer for the sanding means orthe sanding means itself can be arranged there. The sanding meanscomprises, for example, a knitted sanding means fabric and/or anabrasive grit material, for example corundum. The sanding means ispreferably an abrasive sheet. The sanding pad is advantageously suitablefor fastening a sanding sheet on the work surface.

Furthermore, it is possible for a cover body to be arranged on thesupporting wall, which covers the supporting wall and, in particular,also closes recesses on the planar body. The cover body can havethrough-flow openings or through-flow channels and can have the inflowopenings of the sanding pad.

The cover body comprises, for example, an elastic and/or resilientcushion body, for example a kind of pad or is formed by it.

It is preferred if the cushion body is elastic and/or consists of aplastic which is airtight and/or impermeable to dust particles. Forexample, the cushion body consists of foam. In a preferred embodiment,the cushion body comprises or consists of polyurethane foam, inparticular an elastomeric foam based on polyester and/or an aromatic PURelastomeric foam. The cushion body is configured as a pad or cushion,for example.

The cover body can completely or substantially completely cover theplanar body on the machining side. It is preferred if the cover bodycovers the planar body on the machining side except for an edge regionwhich is remote from the drive holder and is provided for engagingbehind the sanding means and/or except for inflow openings orthrough-flow openings for dirty air. For example, there is no adhesivelayer on the edge region, so that the sanding means, for example anabrasive sheet, is removable from the sanding pad. Of course, it isadvantageous if the inflow openings on the machining surface arefluidically connected to and/or communicate with inflow openings orthrough-flow openings of the cover body.

The following embodiment of the cover body forms an advantageousembodiment of the invention, i.e., it is suitable for advantageousarrangement on the planar body. However, it is also possible that thecover body is used on a different sanding pad, for example on a sandingpad that has no cavities and/or is not covered by a sealing element or acover element or both. In particular, it is possible that such a sandingpad has a planar body on which the cover body is arranged according tothe following embodiment, but on which no special measures have beentaken. However, it is advantageous if such a planar body has inflowopenings and outflow openings which are fluidically connected to oneanother by means of through channels, so that dirty air flowing in onthe machining side of the planar body can pass through the throughchannels to the outflow openings, where it can be extracted by, forexample, the suction device, the sanding machine, or the like.

Advantageously or as an independent invention, a cover body is providedfor a sanding pad or as part of a sanding pad, wherein the sanding padis configured in particular according to one of the preceding claims,wherein the cover body is configured as a cushion and has a supportingwall body and a machining wall body, between which an elastic and/orresilient cushion body is held in a sandwich-like manner, wherein thesupporting wall body and the machining wall body have flat sides facingaway from one another, of which the flat side of the supporting wallbody is provided and configured for contact on one or the planar body ofthe sanding pad and the flat side of the machining wall body contains asanding means or an adhesive layer for the detachable fastening of asanding means, in which it is provided that the machining wall body andthe supporting wall body are connected to one another by a connectingdevice on an outer circumference of the cover body, so that the cushionbody is protected against mechanical damage by the supporting wall body,the machining wall body, and the connecting device on the outercircumference of the cover body.

It is a basic concept that the cover body is so to speak reinforced atthe edge, i.e., at its circumference, by the connecting device, at leastit covers the cushion body. Therefore, the cushion body is enclosed in achamber which is provided on the one hand by the supporting wall bodyand the machining wall body on opposite sides of the cushion body, andon the peripheral side by the connecting device. The connecting devicethus preferably forms a reinforcement of the cover body on its outercircumference.

At this point it is to be mentioned that an outer circumference of thecover body preferably essentially has the same contour as an outercircumference of the planar body or disk body of the sanding pad.

It is preferred if the supporting wall body and/or the machining wallbody consist of material which is different and/or has higher tensilestrength than the cushion body. Therefore, the cover body and themachining wall body ensure a protective envelope for the cushion bodyhaving high tensile strength.

The cushion body is preferably a foam body, for example made of apolyurethane foam or the like. Therefore, the cushion body iselastically yielding.

An embodiment would also be conceivable in which the supporting wallbody is not present, i.e., the cushion body bears directly on the planarbody, for example a supporting wall of the planar body, and the planarbody is connected to the machining wall body by the connecting device.

The cushion body consists, for example, of a single foam material orfoamed material or of a combination of at least two foamed materials orfoam materials.

The supporting wall body and/or the machining wall body preferablyconsist of a textile material. In particular, the supporting wall bodyand/or the machining wall body are more closely meshed or less porousthan the cushion body. Compared to the cushion body, the supporting wallbody and the machining wall body are thin, i.e., for example, thecushion body is at least twice as thick, preferably at least three timesas thick as the supporting wall body and the machining wall body.

The textile material of the supporting wall body and/or of the machiningwall body is preferably reinforced, for example by polyamide fibers.

The connecting device comprises, for example, a seam or connectingbodies spaced apart from one another, for example rivets or the like, oris formed by a seam or rivets. The seam or the connecting bodies are,for example, angularly spaced apart from one another. The seam or theconnecting bodies connect the supporting wall body and the machiningwall body, for example directly to one another. However, it is alsopossible that at least one section of the cushion body is penetrated, soto speak, between the supporting wall body and the machining wall bodyby the connecting device, for example the seam, the connecting bodies,and the like. It is preferred if the cover body is edged with the seamon its outer circumference. However, it is also possible that the seamis sewn through the respective front sides or flat sides of thesupporting wall body and machining wall body.

A materially bonded connection is furthermore possible. In this case,the connecting device comprises a material bond or is formed by amaterial bond, for example a welded bond and/or an adhesive bond. Thematerial bond connects the supporting wall body and the machining wallbody to one another, for example directly to one another. It is alsopossible in this case, for example, that an intermediate layer or aportion of the cushion body is adhesively bonded or welded between thesupporting wall body and the machining wall body, wherein the weldingmakes the material of the cushion body stiffer and more resilient on itsouter circumference, so to speak. Alternatively or additionally to anadhesive bond, there can also be an ultrasonic welded bond, for example.Furthermore, the connecting device can be formed by a materialvulcanized onto the machining wall body and the supporting wall body,which at the same time produces a material bond between the two wallbodies.

A ring body is also advantageous as the connecting device, which atleast partially surrounds the outer circumference of the cover body. Forexample, the ring body encloses the cover body like a clasp.

The ring body comprises, for example, at least one peripheral wallcovering the cushion body on the outer periphery of the cover body, or aperipheral wall section. It is also advantageous in the ring body if ithas one or more, for example two, leg sections on which a respectiveflat side of the supporting wall body, a flat side of the machining wallbody, or the planar body of the sanding pad is supported. For example,the supporting wall body, the machining wall body, and the planar bodycan be supported between opposite legs or between legs of the ring body.Therefore, the ring body can also hold the planar body.

The ring body has, for example, a clamp opening or a slot that enablesthe ring body to be fastened on the cover body. Longitudinal ends of thering body, between which the clamp opening or the slot is provided, canbe movable toward one another in the sense of enclosing the cover body.However, it is also possible for several ring segments to be joinedtogether to form the ring body, or the ring body can comprise multiplering segments. It is preferred if the ring body completely oressentially surrounds the outer circumference of the cover body, so thatit is protected as completely as possible on the circumference by thering body.

The ring body can clamp the machining wall body with the supporting wallbody and/or the planar body. For example, the ring body can beconfigured as a bent part.

It is also possible for the ring body to comprise ring bodies lyingopposite to one another and connected in particular by rivets, bolts, orother similar connecting bodies, between which the machining wall bodyand the supporting wall body are held in a sandwich-like mannerFurthermore, it is possible that a section of the planar body, forexample an outer edge section of the planar body, also engages betweenthese ring bodies.

However, the at least one ring body can also comprise or be formed by aring body which is arranged between the supporting wall body and themachining wall body or has a section arranged between the supportingwall body and the machining wall body. For example, the ring body cansurround the cushion body radially on the outside or on the outercircumference of the cover body.

On top: The supporting wall body and/or the machining wall bodiesadvantageously consist of a material that is more impact-resistantand/or denser and/or harder than the cushion body.

The ring body, which is sandwiched between the supporting wall body andthe machining wall body, preferably consists of a ring body that has ahigher tensile strength and/or is more impact-resistant and/or denserthan the cushion body. Furthermore, this ring body can also be made of afoam material or porous or flexible material, for example. However, thismaterial is preferably less porous or stronger or harder or all togetherthan the cushion body.

The ring body can also be elastic and can be deformed by a force actingon the machining wall body in the direction of the supporting wall body.For example, the ring body consists at least partially of rubber orelastic plastic. The ring body can be produced, for example, byvulcanization or can be connected by means of vulcanization to the coverbody, for example the supporting wall body and/or the machining wallbody. Therefore, the ring body preferably forms a wall body that coversthe cushion body radially on the outside or on the outer circumferenceof the cover body.

The cover body expediently has a large-region central region in whichthe cushion body is arranged and around which the connecting deviceextends. In the central region, there is preferably no connectionbetween the machining wall body and the supporting wall body thatpenetrates the cushion body. The advantage here is that in the centralregion the cushion body has its elasticity to the full extent, i.e., itbrings the sanding means arranged on it, for example, flatly intocontact against the workpiece to be processed.

Furthermore, it is advantageous if the machining wall body has alarge-region central region in which the machining wall body projectsfarther in front of the supporting wall body and/or farther in front ofthe planar body than at the outer circumference of the cover body.There, for example, a setback is implemented by the connecting device.However, this setback is advantageously not stepped, but continuous.Therefore, the cover body preferably has a convex or cushion-like shapein the region of the machining wall body.

Inflow openings for dirty air are expediently arranged on the flat sideof the machining body, which are connected to outflow openings on theflat side of the supporting wall body via through channels. dirty aircan flow through the cover body through the through channels. Theoutflow openings of the cover body communicate when mounted on theplanar body of the sanding pad with inflow openings of the planar body,which in turn are fluidically connected via through channels to outflowopenings on the machine side of the sanding pad.

It is possible that the cushion body extends all the way to the outercircumference of the cover body and/or up to the connecting device.However, it is also possible that, for example, a cavity enclosed by thesupporting wall body and the machining wall body, so to speak air, isarranged between the cushion body and the outer circumference of thecover body. This cavity is preferably configured as an annular space.

The cover body having the edge-side connecting device offers a specialadvantage in particular in conjunction with eccentric sanding machines,i.e., in which the sanding pad runs through an eccentric or at leastnon-rotational movement. Thus, if the edge region of the sanding padhits a workpiece or a resistance, the connecting device protects thecushion body from damage.

At this point it is also to be mentioned that the sanding means ispreferably an abrasive sheet which can be removed from the sanding padand held on it detachably.

The adhesive layer comprises, for example, a component of ahook-and-loop connection, for example a hook-and-loop layer orhook-and-loop hooks, for the detachable fastening of the sanding means.

The sanding means can be arranged directly on the cover body, forexample the sanding mat. However, it is also possible for the cover bodyto have or carry the adhesive layer, for example a hook-and-loop layer,for the detachable fastening of the sanding means on the sanding pad.

The invention furthermore relates to a sanding machine having a sandingpad according to the invention and a counter-sealing element for contacton the sealing element of the sanding pad. The counter-sealing elementhas, for example, an elastic ring body made of an elastic material.However, the counter-sealing element can also readily be a plate-shapedbody that slides along the sealing element. In particular, it isadvantageous if the counter-sealing element is held on a housing of thesanding machine in a resiliently yielding manner with respect to thesealing element.

The sanding machine has, for example, a drive motor for driving a toolholder, on which the drive holder of the sanding pad can be detachablyfastened. The drive motor can be an electric motor, for example anelectronically commutated or brushless motor, a universal motor, or thelike. However, the drive motor can also be a compressed air motor. Agear and/or an eccentric bearing for an eccentric mounting of the toolholder with respect to an axis of rotation of the drive motor can bearranged between the tool holder and the drive motor.

In the elastic ring body of the counter-sealing element, one or morecontact bodies are expediently embedded for sanding contact on thesealing element of the sanding pad, wherein the at least one contactbody is made of a material that is harder than the elastic material, forexample metal. Thus, the counter-sealing element is wear-resistant.

Holding pins, in particular several holding pins at an angular spacing,expediently protrude from the sealing element and engage in pinreceptacles of the planar body.

By appropriate geometric configuration of cover and/or sealing element,it is readily possible to set an suction concept of the sanding padindividually. The cavities of the sanding pad are not filled by dust orother material over time, which can negatively influence the runningbehavior or smooth running of the sanding pad or its balancing.

By way of different configuration of sealing elements, for examplegeometric configuration and/or different materials, the suction behavioror suction behavior of the dirty air can be set.

Already existing plate bodies or sanding pads can be retrofitted withthe sealing element. Variants of sanding pads can readily be produced byusing different sealing elements.

The sealing element can readily be replaced when worn.

The material of the sealing element can readily be adapted to theproperties of the counter-sealing element, for example its contactforce, frictional force, or the like, so that matching materialcombinations of sealing element and counter-sealing element areselectable.

An exemplary embodiment of the invention is explained hereinafter withreference to the drawing. In the figures:

FIG. 1 shows a perspective diagonal view of a sanding machine in partialsection having a sanding pad which is shown in

FIG. 2 in an exploded view diagonally from above and in detailenlargements D2, D3, and D4 and in

FIG. 3 assembled diagonally from above,

FIG. 4 shows an exploded view of the sanding pad according to the abovefigures, approximately corresponding to FIG. 2 , but diagonally frombelow and with detail enlargements D5 and D6,

FIG. 5 shows the sanding pad according to the preceding figuresdiagonally from below,

FIG. 6 shows a top view of the sanding pad of the preceding figuresfrontally from above,

FIG. 7 shows a partial portion corresponding to a detail D1,

FIG. 8 shows the partial portion according to detail D1, but along aportion line B-B in FIG. 6 of detail D1,

FIG. 9 shows an exploded view of the sanding machine in partial sectionaccording to FIG. 1 having a sanding pad in a further embodiment,

FIG. 10 shows the sanding pad according to FIG. 9 diagonally from above,

FIG. 11 shows an exploded view of the sanding pad according to FIG. 10diagonally from above,

FIG. 12 shows an exploded view of the sanding pad according to FIGS. 10,11 diagonally from below,

FIG. 13 shows an alternative sealing element for the sanding padaccording to FIGS. 9-12 ,

FIG. 14 shows a section along a section line C-C through the sanding padaccording to FIG. 10 ,

FIG. 15 shows a section along a section line D-D through the sanding padaccording to FIG. 10 ,

FIG. 16 shows a variant of the sanding pad according to the precedingfigures, but with a cover element which is reinforced at the edge by areinforcing device in a first embodiment,

FIG. 17 shows the sanding pad and in particular the cover body accordingto FIG. 16 diagonally from below,

FIG. 18 shows a detail D7 from FIG. 17 ,

FIG. 19 shows a variant of the sanding pad according to FIG. 16 having asmaller cushion body, approximately corresponding to a detail D8 in FIG.16 ,

FIG. 20 shows a further cover body, a variant of a sanding pad, and acover body having a ring body as the connecting device,

FIG. 21 shows a portion through the sanding pad according to FIG. 20 ,approximately corresponding to detail D8 in FIG. 16 ,

FIG. 22 shows the sanding pad according to FIG. 20 diagonally fromabove, but having an alternative ring body,

FIG. 23 shows a partial portion through an edge region of the sandingpad according to FIG. 22 , approximately corresponding to detail D8,

FIG. 24 shows a further sanding pad and a further cover body having anedge-side adhesive bond or weld of the cover body,

FIG. 25 shows a detail of the sanding pad and cover body according toFIG. 24 , approximately corresponding to detail D8,

FIG. 26 shows a further sanding pad and cover body having a stamped andbent part as a ring body and connecting device, of which in

FIG. 27 a detailed portion approximately corresponding to detail D8 isshown,

FIG. 28 shows a further sanding pad and cover body diagonally frombelow, of which in

FIG. 29 a detail portion, for example detail D8 is shown,

FIG. 30 shows a further sanding pad and cover body diagonally from belowhaving an elastic edge protection, which is shown in detail in

FIG. 31 as a portional view (approximately corresponding to detail D8).

A sanding machine 15 is used for sanding a workpiece surface, forexample, a wall surface of a space, a mobile workpiece W, or the like.The sanding machine 15 can be gripped at a handle 16 which, in contrastto the drawing, can be connected to a machine housing 20 of the sandingmachine 15 fixedly or, as shown in the drawing, movably by means of ajoint 17. The handle 16 can be an integral part of the machine body 20and can protrude fixedly therefrom, in contrast to what is shown in thedrawing. The handle 16, which is in particular rod-shaped, allows thesanding machine 15 to be guided along the remote workpiece surfaces, forexample along ceilings or side walls of a room.

A drive motor 25 is accommodated in a motor portion 21 of the machinehousing 20, for example an electronically commutated motor, a universalmotor, or the like. An output 26 of the drive motor 25 drives aneccentric bearing device 27 which supports a tool shaft 28 in arotatable manner, namely by means of one or more pivot bearings. Thebearing device 27 has a tool holder 29 on which a sanding pad 40 can bedetachably fastened using its drive holder 49. The drive holder 49 andthe tool holder 29 have, for example, corresponding screw contours,bayonet contours, or similar other fastening means for detachablefastening. The tool shaft 28 has an eccentricity to a shaft of the drivemotor 25 (not shown in more detail in the drawing), on which the output26 is arranged, i.e., an axis of rotation E of the tool holder 29 iseccentric to an axis of rotation M of the drive motor 25. Therefore, arotational but eccentric sanding movement or drive movement can begenerated by the drive train of the sanding machine 25. Of course, thiseccentricity is only one embodiment, i.e., the sanding machine 25 couldin principle also drive the sanding pad 50 without such an eccentricity,for example if the tool holder 29 were arranged directly on the output26 of the drive motor 25.

The sanding pad 40 is arranged within a protective body 23 which isdesigned, for example, in the manner of an suction hood or protectivehood. The protective body 23 is held by a tool portion 22 of the motorhousing 20 arranged on the motor portion 21 or is integral with it.

A machining face 45 of the sanding pad 40 projects in front of theprotective body 23, i.e., in front of its edge 24 oriented or projectingtowards the machining face 45.

An suction device 30 is used to extract dust that is produced when usingthe sanding machine 15 or the sanding pad 40, namely in that particlesare removed from the workpiece W. The suction device 30 is arranged onthe tool portion 22, for example. The suction device 30 has an suctionfitting 31 to which a hose 12 of an suction device 11, for example avacuum cleaner, is connectable. The suction device 11 generates asuction flow so that dirty air S can be extracted from the region of themachining surface 45. Of course, an suction device or a flow generatorcould also be provided directly on the sanding machine 15, in particulara fan wheel or the like. This can be drivable, for example, by the drivemotor 25 or a separate drive motor.

The suction fitting 31 is fluidically connected to an suction chamber 32which extends around the tool holder 29. If a machine side 41 of thesanding pad 40 is subjected to negative pressure or extracted, theoutflow openings 43 for the dirty air S that are present there and arelocated in the suction chamber 32 are subjected to negative pressure.

Ambient air L furthermore flows from the outside around the sanding pad40, for example through a gap 34 between the protective body 23, thesuction hood, and the sanding pad 40 and/or through through-flowopenings 33 of the protective body 23.

The through-flow openings 33 are provided on an edge region 47 of thesanding pad 40. An suction zone 44 in the center of the sanding pad 40,i.e., an suction zone that extends around the drive holder 49, isdelimited by a sealing arrangement 35, which also encloses or houses thesuction chamber 32.

The sealing arrangement 35 comprises a counter-sealing element 36 of thesanding machine 15 which, when the sanding pad 40 is mounted on thesanding machine 15, bears against a sealing element 80 of the sandingpad 40 to form a seal. The counter-sealing element 36 comprises, forexample, an elastic ring body 37, in particular a type of sealingcollar. The ring body consists for example of elastic plastic, rubber,or the like. The counter-sealing element 36 can have displacementcontours, beads, or the like so that it is deformable relative to thesubstantially rigid or non-elastic sealing element 80.

To reduce wear of the counter-sealing element 36, contact bodies 38 areembedded in the ring body 37 and slide along the sealing element 80 ofthe sanding pad 40. The contact bodies 38 are made of a harder materialthan the ring body 37 and comprise, for example, metal pins.

The machining surface 45 of the sanding pad 40 is arranged on itsmachining side 42. Inflow openings 48 for the inflow of dirty air S arealso located there. The inflow openings 48 communicate withthrough-channels 59 of the sanding pad 40, which are fluidicallyconnected to the outflow openings 43.

The sealing element 80 extends around the suction zone 44 on the machineside 41. The outflow openings 43, which open into the suction chamber32, so to speak, are arranged in the interior of the suction zone 44.The sealing element 80 thus annularly encloses the suction zone 44. Anouter zone 46 is provided radially on the outside with respect to thedrive holder 49, i.e., between the edge region 47 or the outercircumference of the sanding pad 40 and the sealing element 80, which isclosed off towards the machine side 41, namely by a cover element 70.Only radially on the outside with respect to the drive holder 49, the inthe edge region 47, a rib structure 45 of the sanding pad 40 is open,but not to the side 41, but also to the outer edge of the sanding pad40, so that no dust deposits or the like are to be feared there.

The sanding pad 40 experiences its rigidity essentially due to theplanar body 50, which is essentially rigid. For example, the planar body50 consists of metal, of a thermosetting plastic, or the like. Inaddition, the planar body 50 is reinforced by the rib structure 45.

The planar body 50 is provided on its machine side 51 with a pluralityof cavities 57 which are located between ribs 56 of the rib structure55. The cavities 57 result essentially due to the demolding of theplanar body 50 in the context of a casting process, for example when acasting core GK (shown schematically in FIG. 3 ) is removed from arespective cavity 57. Intermediate spaces between the ribs 56, thereforecavities 57, are thus open, while sections of a supporting wall 54extend between the ribs 56 on the machining side 52 of the planar body50.

At this point, however, it is to be mentioned that the supporting wall54 has a plurality of recesses 59A, which communicate with the inflowopenings of the sanding pad 40 or form them. portions of the recesses59A can be represented by inflow openings 58, for example. Thethrough-channels 59 communicate with outflow openings 53 on the machineside of the planar body 50 so that dirty air flowing into the recesses59A and the inflow openings 58 can flow through the through-channels 59to the outflow openings 53.

Insofar as the planar body 50 is open on its machining side 52 due tothe recesses 59A, it is in any case closed or covered by a cover body560.

The cover body 560 is arranged with its machine side 61 on the machiningside 52 of the planar body 50, for example adhesively bonded to theplanar body 50, connected in a form-fitting manner (not shown), or thelike.

The cover body 560 has a plate-like shape. The cover body 560 has, forexample, through-flow openings 63 which are fluidically connected to theinflow openings 58 of the planar body 50 or communicate with them.Furthermore, a passage opening 569 is provided on the cover body 560 inthe region of the drive holder 49, so that, for example, a fasteningscrew or the like, using which the sanding pad 40 is connectable to thetool holder 29, is actuatable.

On its machining side 62, the cover body 560 preferably has an adhesivelayer 66, for example a hook-and-loop layer, an adhesive layer, or thelike, for a sanding means 90, in particular an abrasive sheet 90A. Ofcourse, instead of the adhesive layer 66, a sanding means, for example agrit, a sanding means fabric, or the like, could be arranged directly.

The planar body 50 is essentially covered by a cover element 70 on themachine side 51.

The cover element 70 extends into the outer zone 46 and covers the ribstructure 55 there towards the machine side. Thus, no dust or any otherundesirable material can penetrate into the cavities 57 of the outerzone 46. The cover element 70 also essentially covers the cavities 57 ofthe rib structure 55 radially on the inside with respect to the sealingelement 80.

A machining side 72 of the cover element 70 rests on the ribs 56 andcan, for example, be adhesively bonded and/or welded to them, forexample thermally welded.

In the exemplary embodiment, the cover element 70 is held in aform-fitting manner on the planar body 50, namely by the sealing element80. Thus, for example, through-flow openings 73 of the cover element 70are aligned with the outflow openings 53 of the planar body 50, so thatthey can represent the outflow openings 43 of the sanding pad 40. Thisis because the cover element 70 is not only provided in the region ofthe outer zone 46 to cover part of the cavities 57, but also in thesuction zone 44. There the cover element 70 covers all the cavities 57of the rib structure 55, except for the outflow openings 53 and thedrive holder 49, for which through-flow opening 73 or passage openings79, respectively, are provided.

The cover element 70 has further passage openings 78, namely for holdingprojections 89 and thus holding contours 88 which engage in the holdingreceptacles or passage openings 78 in a form-fitting manner For example,the holding projections 85 are polygonal or are provided in some otherway with an anti-twist contour on their outer circumference, i.e.,around their respective plug axis along which they are pluggable intothe holding receptacles 78.

The sealing element 80 has a sealing body 83A which has a passageopening 83 and thus has an annular shape. The inner peripheral contourof the sealing body 83A delimiting the passage opening 83 delimits thesuction zone 44. On the sealing body 83A, which is wall-like orplate-like, for example, a sealing surface 83B is provided on themachine side 81 of the sealing element 80, against which thecounter-sealing element 36 can bear to form a seal, i.e, for example,can rub along.

The holding projections 89 penetrate the holding receptacles 78 orpassage openings of the holding element 70 and protrude freely into thecavities 57. Of course, plug receptacles or similar other form-fittingholding contours could also be provided for the holding projections 89,so that the sealing element 80 can be fastened directly to the planarbody 50 in a form-fitting manner by means of the holding projections 89.Such a form-fitting support enables, for example, support against adirection of force F, which extends parallel to the machining surface45. Thus, for example, a torque generated by the sealing elements 36 and80 rubbing against one another is supported on the planar body 50.

The sealing element 80 is connected in a form-fitting manner, namelylatched, directly to the planar body 50 using latching means 84. Thelatching means 84 include form-fitting projections 85 which protrudetowards the machining side 82 of the sealing element 80 and engage in aform-fitting manner in form-fitting receptacles 95 of the planar body50. The form-fitting projections 85 and the form-fitting receptacles 95are, for example, plug projections and plug receptacles.

The form-fitting projections 85 could engage in the form-fittingreceptacles 95, for example with a press fit, which results, forexample, in that the form-fitting projections 85 have slots 85C, 85D, sothat plug segments 85A, 85B are formed, which are relatively movabletoward one another and away from one another transversely to a plug axisSA. In particular, such a press fit is provided on lateral supportsurfaces 98 of the form-fitting receptacle 95, using which therespective form-fitting projection 85 for supporting the force F issupported on the form-fitting receptacle 95. The support surfaces 98support, for example, a base region of a respective form-fittingprojection 85, using which it is connected to the sealing body 83A.

The form-fitting projections 85 are configured, for example, likeholding pins that engage in the holding receptacles or form-fittingreceptacles 95.

Rear gripping surfaces 97 are provided counter to a plug axis direction,along which the form-fitting projections 85 are inserted into theform-fitting receptacles 95. The rear gripping surfaces 97 are locatedin an expanded section 96 of a respective form-fitting receptacle 95,into which a head region 86 of a respective form-fitting projection 86engages. The head region 86 also has rear gripping surfaces 87 whichprotrude transversely to the plug axis SA in front of the base region orbase section of a respective form-fitting projection 85. Theform-fitting projections 85 are thus supported in a form-fitting mannerin the form-fitting receptacles 95 in the direction of a removal of thesealing element 80 from the planar body 50. When the form-fittingprojection 85 is inserted into the form-fitting receptacle 95, the plugsegments 85A, 85B are displaced toward one another in the direction ofthe slots 85C, 85D or in the direction of a narrowing of the slots 85C,85D, so that the head regions 86 can reach the widened portion 96 of theform-fitting receptacle 95 past the support surfaces 98 and latch therewith the form-fitting receptacle 95.

The slots 85C, 85D extend, for example, in a cross shape and/or at anangle to one another.

Additionally or alternatively to the latching means 84, an adhesive bondof the sealing element 80 to the planar body 50 can also be provided.

Alternatively, it is also possible, for example, for form-fittingprojections to protrude from the planar body and engage in form-fittingreceptacles of a sealing element. Therefore, for example, projectionscould be provided on the planar body 50 which engage in form-fittingreceptacles, which are provided instead of the form-fitting projections85, of the sealing element 80.

The form-fitting projections 85 are arranged at angular intervals,preferably equal or equidistant angular intervals, on the sealingelement 80 and protrude toward the machining side 82 of this element.The form-fitting projections 85 penetrate passage openings 75 of thecover element 70 so that this is held in a sandwich-like manner betweenthe sealing element 80 and the planar body 50.

The holding contours 88 or holding projections 89 form additionalholding elements which fix the cover element 70 with respect to theplanar body 50. The holding projections 89 are, for example, likewisearranged at angular intervals from one another, in particular at regularangular intervals from one another. It can be provided that a holdingprojection 89 is provided next to or on each, preferably only everysecond, form-fitting projection 85.

Instead of the cover body 560, on which a sanding means in the form ofthe abrasive sheet 90A can be arranged directly, a cover body 60 canalso be provided.

The cover body 60 is fastened to the planar body 50 with a machine side61, for example adhesively bonded thereon or connected detachably to it,which will become even clearer hereinafter. For example, a supportingwall body 64 of the cover body 60 bears against the planar body 50.

On a machining side 62 opposite to the machine side 61, the cover body60 has a machining wall body 65, which is used to fasten and support thesanding means 90, in particular the sanding means 90A. An adhesive layer66 is arranged on the machining wall body 65, for example, which can beconnected to the adhesive layer 94 of the sanding means 90, for examplein the manner of a hook-and-loop connection.

A cushion body 67 made of a foam material or other elastic material isarranged between the supporting wall body 64 and the machining wall body65, so that the machining side 62 or the machining wall body 65 candeform with deformation of the cushion body 67 in the direction of themachining side 52 of the planar body 50 in order to conform to contoursof the workpiece W.

The supporting wall body 64 and the machining wall body 65 have flatsides 64F, 65F facing away from each other, of which the flat side 64Fof the supporting wall body 64 is provided and configured for contact onthe planar body 50 of the sanding pad 60, 160 and the flat side 65F ofthe machining wall body 65 has the adhesive layer 66

The cover body 60 has through-flow openings 63 which, when the coverbody 60 is mounted on the planar body 50, are aligned with the inflowopenings 58, so that dirty air S, which flows through the through-flowopenings 93 of the sanding means 90 into the cover body 60, flows intothe inflow openings 63E of the cover body 60 and through through-flowopenings 63, can flow out of outflow openings 63A of the cover body 60and can furthermore flow through the planar body 50.

Instead of the adhesive layer 66, a sanding means, for example anabrasive fabric, a grit material, or the like, could readily be arrangeddirectly on the cover body 60 or 560.

The cover body 60 is adhesively bonded on the planar body 50, forexample.

On the other hand, the cover body 60 is advantageously releasablyfastenable on a planar body 150 of a sanding pad 140, namely, forexample, by means of screws 68B that are inserted through passageopenings 68 in the cover body 160 and screwed into screw receptacles 68Dof the planar body 150 that are arranged on its machining side 52. Thescrews 68B have screw heads 68C, which are supported on the machiningside 62 of the cover body 60, which is configured as a flat side.Contrary to what is shown in the drawing, but as indicated bydash-dotted lines in FIG. 14 , the screw heads 68C plunge into themachining side 52 or the machining wall body 65 in such a way thattroughs are formed therein which the screw heads 68C are accommodated,and a substantially flat surface 62B results on the machining side 62.To form such troughs, slots 68A extend from the passage openings 68, forexample in a star shape, which enable or facilitate a deformation ortrough formation of the cover body 60 in the region of the screw heads68C.

The sanding pad 160 has the above-mentioned planar body 150, which has amachine side 51 on which a drive holder 149 is provided. The driveholder 149 is used to fasten a tool holder 129, which has certaindifferences from the tool holder 59, but also has an eccentric bearingdevice 27. Holding projections 29A are provided on its outercircumference, on which screw receptacles 29B are arranged. The holdingprojections 29A are preferably accommodated in the drive holder 149 in aform-fitting manner, for example by means of matching receptaclecontours. However, this is not absolutely necessary, namely becausescrews 29C are provided which penetrate passage openings 29D of theplanar body 150 and are screwed into the screw receptacles 29B.

The planar body 150 is constructed similarly to the planar body 50,i.e., it has a supporting wall 54 and inflow openings 58 on itsmachining side, which are fluidically connected via through-channels 59to outflow openings 53 of a machine side 51 of the planar body 150. Arib structure 155 stiffens and supports the supporting wall 54 and isopen toward the machine side 51, i.e., cavities 57 are present betweenribs 156 of the rib structure 155. These cavities 57 are also covered onthe machine side 51 in the case of the planar body 150 and thus thesanding pad 140, so that dust and similar other undesirable materialdoes not penetrate into the cavities 57.

The sanding pad 160 has a sealing element 180 which is integrallyenclosed by cover element 170. A machine side 81 of the sealing element80 is used to ensure that the elastic ring body 37 and/or thecounter-sealing element 36 bears against it to form a seal. An annularsealing surface 83B is provided on a sealing body 83A of the sealingelement 180 for sealing contact of the counter-sealing element 36 andextends around a passage opening 83 of the sealing element 180. Thecover element 170 is arranged radially on the outside on the sealingelement 180, which annularly encloses the sealing element 180 with aring body 174, which has an annular shape.

The sealing element 180 is connected to the planar body 150 by means ofa weld and essentially covers its cavities 57, except for rib structureswhich are open radially outwards with respect to the sanding pad 140.

Both the sealing element 180 and the cover element 170 are plate-shaped.The sealing element 180 protrudes in front of the cover element 170 in adirection away from the planar body 150. Holding contours 188 can beprovided on the sealing element 180, for example holding projections,which engage in the planar body 150, for example are supported on theribs 156 of its rib structure 155.

Furthermore, form-fitting contours are advantageously provided on themachine side 51 of the planar body 150 and the machining side 82 of thesealing element 180 which advantageously and/or at least during anassembly process and/or welding process of the two components interlockin a form-fitting manner and hold the two components relative to eachother, so that the welding described hereinafter succeeds with optimalaccuracy. For example, form-fitting projections 158A are provided on themachine side 51 of the planar body 150, for example in the form ofcentering projections or centering pins, which engage in form-fittingreceptacles 178 of the cover element 170. The pairs of form-fittingreceptacle 170 and form-fitting projections 158A are provided at angularintervals with respect to the axis of rotation or central axis of thesanding pad 140.

Welding projections 185 are provided on the machining side 82 of thesealing element 180 and on the machining side 72 of the cover element170, i.e. on the same side of both components, which projections aresupported on the ribs 156 and are connected to them by means ofultrasonic welding. The welding projections 185 extend partiallyannularly around the outflow openings 53 of the planar body 50 and tothis extent close through-channels 59 via which inflowing dirty air canflow via the inflow openings 58 on the machining side 52 of the planarbody 50. The course of the welding projections 185 is adapted to thecourse of the ribs 156 and has, for example, portions 185A extendingapproximately parallel to the outer circumference of the drive holder149, from which portions 185B extend away in the direction of the driveholder 149 and up to it.

The sealing element 180 thus covers or seals the radially inner regionof the machine side 51 of the planar body 150 surrounding the driveholder 159 and is welded to this region. The cavities 57 are coveredradially on the outside by the cover element 170, which rests tightly onthe end faces of the ribs 156, but is not or not completely welded tothem. However, welding projections 177, for example punctiform weldingprojections, are provided radially on the outside with respect to theaxis of rotation of the sanding pad 140 on the machining side 72 of thecover element 170 and are welded to the material of the planar body 150.For example, multiple welding projections 177 are provided arrangedadjacent to one another at angular intervals in the circumferentialdirection with respect to the axis of rotation of the sanding pad 140.The welding projections 177 are arranged on the radially outer edgeregion of the cover element 170 with respect to the axis of rotation ofthe sanding pad 140.

Multiple, for example four, welding projections 177 form a weldingprojection group, for example. Between the welding projection groups ofwelding projections 177, there are preferably angular intervals in whichno welding projections are provided. The welding projections 177preferably form multiple row arrangements.

In the example of a sealing element 180A, which in principle correspondsto the sealing element 180 including the cover element 170 arrangedthereon, there are welding projections which have a linear shape andalso enable optimal welding to the planar body 150 in the region of thecover element 170. For example, peripheral welding projections 185Dextending on the outer circumference of the cover element 170 areprovided. Annular welding projections 185E also extend, for example,around the screw receptacles 86D. Furthermore, further weldingprojections 185C extend radially outwards in a star shape in the regionof the cover element 170. Overall, the welding projections of thesealing element 180 basically form a rib-like shape which is, so tospeak, complementary to the rib structure 155 and thus comes to rest onor adjacent to the end faces of the ribs 156. With a correspondinglypowerful welding system, for example at 20 kilowatts and more, elongatedwelding projections and a large number of welding projections, as in thecase of the sealing element 180A, can also be welded using ultrasound.

The cushion body 67 of the cover body 60 is exposed on the outercircumference 69 of the cover body 60. As a result, for example, it isnot protected against damage if the sanding pad 140 hits an obstacle.

To remedy this problem, alternative covering bodies 60A, 60B, 60C, 60D,60E, 60F, 60G are provided to cover body 60, on the outer circumference69 of which a connecting device 100A, 100B, 100C, 100D, 100E, 100F, 100Gis provided. The connecting device 100A-100G protects the respectiveouter circumference 69 against damage, namely in that the cushion body67 is protected by the connecting device 100A-100G, which may also bereferred to hereinafter as the connecting device 100 for the sake ofsimplicity. The basic structure of the covering bodies 60A, 60B, 60C,60D, 60E, 60F, 60G corresponds to the cover body 60, i.e., they havesupporting wall bodies 64 and machining wall bodies 65, between which acushion body 67 is accommodated in a sandwich-like manner in each case.

For example, a seam 101 is provided in the cover body 60A, whichdirectly connects the supporting wall body 64 and the machining wallbody 65 to one another. The seam 101 is preferably configured as azigzag seam. It is particularly advantageous if the seam 101 isconfigured as a type of edge.

The supporting wall body 64 and/or the machining wall body 65 consists,for example, of rubber, cloth, composite materials, or the like.

The supporting wall body 64 and the machining wall body 65 are, so tospeak, connected to one another at the edge by the connecting device100A. One advantageous effect is that the connecting device 100A, inparticular the seam 101, forms a peripheral part 69B on the outercircumference 69, in which or on which the wall bodies 64 and 65 arearranged directly adjacent to one another and are fixedly connected toone another. Proceeding from this, an inclined part 69A of the outercircumference 69 extends to a flat or essentially flat fastening plane69C, which is provided for fastening the sanding means 90. The inclinedpart 69A extends obliquely with respect to the fastening plane 69C.

The fastening plane 69C is preferably a flat plane in front of which theheads of the screws 68B do not protrude, namely by plunging into theslots 68A or troughs of the cushion body 67.

Alternatively or additionally to the seam 101, a material connection101A, for example welding, adhesive bonding, etc., is also possible. Inall of these cases, the wall bodies 64 and 65 are connected directly toone another, so that the cushion body 67 is enclosed on the outercircumference 69 and is not freestanding.

In order to be able to form the inclined part 69A better, a cavity 67Ais provided between the cushion body 67 and the outer circumference 69,for example. This is the case, for example, in a cover body 60A2.

Advantageously, the fastening plane 69C and/or thus a middle or centralregion or central region 69Z or the largest surface extension of themachining side 62 of the cover body 60A is configured in such a way thatthere is no connection penetrating the cushion body 67 and thesupporting wall body 64 and the machining wall body 65 there, forexample, no part of the connecting device 100, i.e., for example noseam, no material bond, or the like. Although this would be possible inprinciple, under certain circumstances it would have the result that thefastening plane 69C would have troughs or similar other indentations.

In the case of a connecting device 100B, a ring body 102 is providedwhich, so to speak, encloses the supporting wall body 64, the machiningwall body 65, and also the supporting wall 54. The ring body 102 has,for example, a peripheral wall portion 102A from which leg portions102B, 102C project at an angle, for example at right angles. A U-shapedreceptacle is thereby formed, in which a peripheral part 65A of themachining wall body 65 as well as a peripheral part 64A of thesupporting wall body 64 are accommodated.

The ring body 102 preferably has a slot or clamp opening 102D so that itis installable like a clamp around the outer circumference of thesanding pad 140, enclosing the planar body 150 and the cover body 60B.

A connecting device 100C has a similar concept as the connecting device100B, wherein in contrast to the ring body 102, a ring body 103 onlyclamps the supporting wall body 64 and the machining wall body 65together, so to speak. The ring body 103A has a peripheral wall portion103 from which leg portions 103B and 103C project at an angle, so that areceptacle is thus formed in which the peripheral parts 65A of thesupporting wall body 64 and the machining wall body 65 are accommodated.

Like the ring body 102, the ring body 103 also has a slot or clampopening 103D so that it can be arranged on the cover body 60C enclosingit like a clamp. In doing so, it engages, for example, in a depressionor peripheral receptacle 54A of a planar body 150C, which is arranged onthe outer circumference of its supporting wall 54 and/or is openradially outwards. Otherwise, the planar body 150C corresponds to theplanar body 150.

However, the planar body 150C is also suitable for a connecting device100D which has a two-part ring body 104, so to speak. This isconfigured, for example, as a stamped and bent part. A ring element 104Aand a ring element 104B are, for example, welded to one another and/oradhesively bonded to one another, for example in the region of aperipheral part 104E of the ring element 104A. A peripheral wall portion104C extends from this peripheral part 104E in a direction away from thering element 104B, while a leg 104B in turn lies opposite the ringelement 104B, so that between these two latter components there is areceptacle into which the peripheral wall parts 64A and 65A engage or inwhich they are accommodated.

An alternative concept to this is implemented in a connecting device100E, the ring body 105 of which has ring elements 105B and 105C, whichaccommodate the peripheral parts 64A and 65A in a sandwich-like mannerand connect them to one another. The ring elements 105B and 105C are,for example, annular, in particular circularly annular, plate bodies orwall bodies which face toward one another with their end faces or flatsides, wherein the peripheral part 65A of the machining wall body 65 andthe one peripheral part 64A of the supporting wall body 64 areaccommodated between the end faces or flat sides.

For example, the ring elements 105B and 105C are connected to oneanother by connecting bodies 105A, e.g., rivets, screws, or the like,which penetrate both the ring elements 105B and 105C and also thesupporting wall body 64 and the machining wall body 65 and thus fixedlyconnect all components to one another. As a result, the cover body 60Eis compacted at its outer periphery 69 and is hard and advantageouslyimpact-resistant. However, it would also be conceivable that the ringelements 105B and/or 105C are not provided, wherein then the connectingbodies 105A connect peripheral parts 64A and 65A directly to oneanother. It can be provided that only one of the ring elements 105Band/or 105C is present.

However, a relatively soft outer circumference of the cover element 60Falso offers optimal protection for the cushion body 67. For example, aring body 106 of the connecting device 105 is made of an elasticmaterial, e.g., plastic, rubber, or the like. The ring body 106 has aperipheral wall 106A, which preferably has wall parts 106B which aremovable relative to one another. For example, the wall parts 106B arealigned in a V-shape or are in a V-shape relative to one another. Wallportions 106C and 106D extend away from the peripheral wall 106A and areconnected to the supporting wall body 64 and the peripheral wall body65, for example by material bonding, adhesive bonding, or the like. wallpo

Furthermore, a part 106E of the ring body 106 engages in theabove-explained receptacle 64A of the planar body 150C. It isadvantageous if the planar body 150C having the supporting wall 64protrudes approximately up to the peripheral wall portions 106D and106C, so that it can implement additional mechanical protection for thecushion body 67.

However, a material which is more wear-resistant than the cushion body67 but which is nevertheless flexible and is accommodated between thewall bodies 64 and 65 can also represent a connecting device, as is thecase with the connecting device 100G. There, for example, a ring body107 is formed from a foam material which is more wear-resistant than thefoam material of the cushion body 67, for example harder, and/or moreclosed cell or the like. The ring body 107 extends to the outercircumference 69, where it is frontally open, i.e., is not covered bythe supporting wall body 64 or the machining wall body 65, for example.However, since the ring body 107 is more mechanically resilient than thecushion body 67, it is less sensitive to impact loads than the cushionbody 67. A thickness of the ring body 107 is advantageously selected sothat it is less than a thickness of the cushion body 67, wherein thethickness represents the distance between the supporting wall body 64and the machining wall body 65. Thus, from the central region or mainsurface region of the cover body 60G, an inclined part 69A extends to aperipheral part 69B which is set back in relation to the centralportion.

It can be seen that the supporting wall body 64 is not necessary in allcases. For example, it would be possible that in the exemplaryembodiment of the cover body 60C, there is no supporting wall body 64,wherein then the ring body 103 connects the machining wall body 65directly to the supporting wall 54, so that the cushion body 67 isenclosed between the supporting wall 54 and the machining wall body 65.In this case, the ring body 103 provides sufficient protection on theouter circumference 69.

Such a procedure is also possible in the other exemplary embodiments,i.e., there is no supporting wall body. For example, in the exemplaryembodiment of the cover body 60A, the machining wall body 65 can beconnected directly to the planar body 50, i.e., the supporting wall 54,at the outer circumference 69, for example, by a seam, a weld, or thelike.

1. A sanding pad for a sanding machine, comprising a drive holder,situated on a machine side of the sanding pad, to be fastened in anon-rotatable manner to a drive of the sanding machine, such that thesanding pad can be driven by the sanding machine; wherein the sandingpad comprises a machining side, which is opposite the machine side andhas a machining face on which a sanding means for abrasive machining ofa workpiece can be arranged so as to be fixed or removable using anadhesive layer, wherein inflow openings for dust-laden dirty air to flowin are situated in the machining face, and outflow openings fluidicallyconnected to the inflow openings via through-channels are situated onthe machine side; wherein the outflow openings are situated in a suctionzone within an annular sealing element that is situated on the machineside for sealingly contacting a counter-sealing element of the sandingmachine, wherein the sanding pad comprises a planar body which has asupporting wall provided for supporting the sanding means, whichsupporting wall is reinforced by a rib structure, the ribs of whichproject beyond the supporting wall towards the machine side, wherein theribs delimit cavities which are closed by the supporting wall withrespect to the machining side and are open with respect to the machineside, and wherein the sealing element covers at least some of thecavities towards the machine side.
 2. The sanding pad of claim 1,wherein the sealing element and the planar body are integral or thesealing element and the planar body are separate components which arefixedly connected to one another.
 3. The sanding pad of claim 1, whereinat least one cavity covered by the sealing element on the machine sideis a demolding cavity formed by removing a casting core from the cavity.4. The sanding pad of claim 1, wherein the sealing element, except forthe outflow openings, covers and/or tightly closes all cavities of theplanar body within the suction zone and/or on a flat side of the planarbody and/or between the drive holder and an edge region of the planarbody.
 5. The sanding pad of claim 1, wherein the sealing element, exceptfor the outflow openings, tightly closes at least a part of thecavities, so that a volume located in the respective cavity is closeddust-tight.
 6. The sanding pad of claim 1, wherein the sealing elementcovers and/or tightly closes at least one, multiple, or all of thecavities provided and configured to form one or more through channelsand/or at least one or all through channels.
 7. The sanding pad of claim1, wherein the sealing element rests flatly on the end faces of the ribsfacing toward the sealing element.
 8. The sanding pad of claim 1,wherein the sealing element is connected by means of welding, and/oradhesive bonding to the planar body.
 9. The sanding pad of claim 1,wherein the sealing element and/or the planar body have at least onewelding projection, for welding to the respective other component of thesealing element or planar body or are welded by means of the at leastone welding projection to the respective other component of sealingelement or planar body.
 10. The sanding pad of claim 1, wherein theplanar body and the sealing element are supported on one another in aform-fitting manner in a force direction parallel to the workingsurface.
 11. The sanding pad of claim 1, wherein the sealing element isdetachably arranged on the planar body.
 12. The sanding pad of claim 1,wherein the sealing element and the planar body are connected to oneanother in a form-fitting manner by at least one pairing of aform-fitting projection and a form-fitting receptacle which extendtransversely, to the machining surface and interlock.
 13. The sandingpad of claim 1, wherein the sealing element has at least one supportcontour and/or a support rib projecting in front of the sealing elementfor lateral contact on a rib delimiting a cavity.
 14. The sanding pad ofclaim 13, wherein the sealing element has two support contours and/orwelding projections spaced apart from one another, which are providedfor contact on opposite ribs delimiting a cavity or delimit a receptaclefor engaging a rib.
 15. The sanding pad of claim 13, wherein the atleast one support contour or the at least one welding projection has atleast two support contours or welding projections extending at an angleto one another, for support on ribs angled in relation to one another.16. The sanding pad of claim 13, wherein the at least one supportcontour or the at least one welding projection comprises a support framefor lateral contact on an inner circumference of a cavity delimited byribs of the rib structure.
 17. The sanding pad of claim 13, wherein theat least one support contour forms or comprises a welding projection forthermal welding and/or ultrasonic welding of the sealing element to theplanar body.
 18. The sanding pad of claim 1, further comprising a coverelement which covers at least part of the cavities on the machine side.19. The sanding pad of claim 18, wherein the cover element is held onthe planar body in a form-fitting manner and/or by means of the sealingelement and/or by means of an adhesive bond and/or is integrally formedor fixedly connected with the sealing element or is formed by thesealing element.
 20. The sanding pad of claim 18, wherein the coverelement has openings, for form-fitting elements, using which the sealingelement and the planar body are fixed on one another in a form-fittingmanner, and/or for engaging holding contours of the sealing elementand/or for through-flow of dirty air and/or for the drive holder. 21.The sanding pad of claim 1, wherein the sealing element and/or the or acover element at least partially covering the cavities of the planarbody, except for the outflow openings for the dirty air outside and/orinside the suction zone cover all cavities of the planar body on themachine side, which are closed between the machine side and themachining side or to an outer edge of the sanding pad with respect to anouter circumference of the planar body.
 22. The sanding pad of claim 1,wherein at least a part of the ribs of the planar body extend radiallyor radiating away from the drive holder to an edge region of the sandingpad.
 23. The sanding pad of claim 1, wherein at least a part of the ribsof the planar body extend to a common support plane, in which the ribssupport the sealing element and/or the cover element.
 24. The sandingpad of claim 1, wherein the supporting wall of the planar body hasrecesses on the machining side to form the inflow openings and/or toprovide at least partial portions of the through-channels.
 25. Thesanding pad of claim 1, wherein the machining face of the sanding pad isprovided directly by the supporting wall or a cover body having themachining face.
 26. The sanding pad of claim 25, wherein the cover bodyhas or is formed by an elastic and/or resilient cushion body and/or thecover body covers the planar body on the machining side completely orexcept for an edge region which is remote from the drive holder andprovided for reaching behind the sanding means and/or through-flowopenings for dirty air and/or wherein the cover body has the sandingmeans or the adhesive layer for the detachable fastening of the sandingmeans on the sanding pad.
 27. The sanding pad of claim 25, wherein thecover body is detachably fastened on the planar body by means offastening bolts.
 28. A cover body for a sanding pad or as part of asanding pad, wherein the sanding pad comprises a machining side and hasa machining face on which a sanding means for abrasive machining of aworkpiece can be arranged so as to be fixed or removable using anadhesive layer, wherein inflow openings for dust-laden dirty air to flowin are situated in the machining face, and outflow openings fluidicallyconnected to the inflow openings via through-channels are situated onthe machine side; wherein the outflow openings are situated in a suctionzone within an annular sealing element that is situated on the machineside for sealingly contacting a counter-sealing element of the sandingmachine, wherein the sanding pad comprises a planar body which has asupporting wall provided for supporting the sanding means, whichsupporting wall is reinforced by a rib structure, the ribs of whichproject beyond the supporting wall towards the machine side, wherein theribs delimit cavities which are closed by the supporting wall withrespect to the machining side and are open with respect to the machineside, and wherein the sealing element covers at least some of thecavities towards the machine side, wherein the cover body is configuredas a cushion and has a supporting wall body and a machining wall body,between which an elastic and/or resilient cushion body is held in asandwich-like manner, wherein the supporting wall body and the machiningwall body have flat sides facing away from one another, of which theflat side of the supporting wall body is provided and configured forcontact on one or the planar body of the sanding pad and the flat sideof the machining wall body contains a sanding means or an adhesive layerfor the detachable fastening of a sanding means, wherein the machiningwall body and the supporting wall body are connected to one another by aconnecting device on an outer circumference of the cover body, so thatthe cushion body is protected against mechanical damage by thesupporting wall body, the machining wall body, and the connecting deviceon the outer circumference of the cover body.
 29. The cover body ofclaim 28, wherein the supporting wall body and/or the machining wallbody consist of material which is different and/or has higher tensilestrength and/or is more impact-resistant and/or denser and/or harderthan the cushion body.
 30. The cover body of claim 28, wherein thesupporting wall body and/or the machining wall body consist of a textilematerial.
 31. The cover body of claim 28, wherein the connecting devicecomprises a seam or connecting bodies spaced apart from one another oris formed by a seam or connecting bodies spaced apart from one another,wherein the seam or the connecting bodies connect the supporting wallbody and the machining wall body to one another, in particular directly.32. The cover body of claim 28, wherein the connecting device comprisesa material bond or is formed by a material bond, wherein the materialbond connects the supporting wall body and the machining body to oneanother.
 33. The cover body of claim 28, wherein the connecting devicecomprises at least one ring body which at least partially encloses theouter circumference of the cover body.
 34. The cover body of claim 33,wherein the at least one ring body has at least one peripheral wallportion overlapping the cushion body on the outer circumference of thecover body and/or has at least one leg portion on which a flat side ofthe supporting wall body or a flat side of the machining wall body orthe planar body of the sanding pad is supported.
 35. The cover body ofclaim 33, wherein the at least one ring body clamps the machining wallbody to the supporting wall body and/or the planar body and/or comprisesring bodies that are opposite to one another and are connected to oneanother, and between which the machining wall body and the supportingwall body are held in a sandwich-like manner
 36. The cover body of claim33, wherein the at least one ring body is arranged in a sandwich-likemanner between the supporting wall body and the machining wall body orhas a section arranged between the supporting wall body and themachining wall body.
 37. The cover body of claim 33, wherein the ringbody is elastic or has an elastic part and is deformable by a forceacting on the machining wall body in the direction of the supportingwall body.
 38. The cover body of claim 28, further comprising alarge-region central region in which the cushion body is arranged andaround which the connecting device extends, and wherein in the centralregion there is no connection penetrating the cushion body between themachining wall body and the supporting wall body.
 39. The cover body ofclaim 28, wherein the machining wall body has a large-region centralregion in which the machining wall body projects farther in front of thesupporting wall body than on the outer circumference of the cover body.40. The cover body of claim 28, wherein inflow openings for dirty airare arranged on the flat side of the machining wall body and areconnected to outflow openings on the flat side of the supporting wallbody via through-channels.
 41. The cover body of claim 28, wherein acavity enclosed by the supporting wall body and the machining wall bodyis provided between the cushion body and the outer circumference of thecover body.
 42. A sanding machine having a drive motor for driving anoutput and having a sanding pad for fastening on the output, the sandingpad comprising a machining side and has a machining face on which asanding means for abrasive machining of a workpiece can be arranged soas to be fixed or removable using an adhesive layer, wherein inflowopenings for dust-laden dirty air to flow in are situated in themachining face, and outflow openings fluidically connected to the inflowopenings via through-channels are situated on the machine side; whereinthe outflow openings are situated in a suction zone within an annularsealing element that is situated on the machine side for sealinglycontacting a counter-sealing element of the sanding machine, wherein thesanding pad comprises a planar body which has a supporting wall providedfor supporting the sanding means, which supporting wall is reinforced bya rib structure, the ribs of which project beyond the supporting walltowards the machine side, wherein the ribs delimit cavities which areclosed by the supporting wall with respect to the machining side and areopen with respect to the machine side, and wherein, characterized inthat the sealing element covers at least some of the cavities towardsthe machine side and/or having a sanding pad on which a cover body isarranged, the cover body being configured wherein the cover body isconfigured as a cushion and has a supporting wall body and a machiningwall body, between which an elastic and/or resilient cushion body isheld in a sandwich-like manner, wherein the supporting wall body and themachining wall body have flat sides facing away from one another, ofwhich the flat side of the supporting wall body is provided andconfigured for contact on one or the planar body of the sanding pad andthe flat side of the machining wall body contains a sanding means or anadhesive layer for the detachable fastening of a sanding means,characterized in that, wherein the machining wall body and thesupporting wall body are connected to one another by a connecting deviceon an outer circumference of the cover body, so that the cushion body isprotected against mechanical damage by the supporting wall body, themachining wall body, and the connecting device on the outercircumference of the cover body, wherein the sanding machine has acounter-sealing element for contact on the sanding pad and/or thesealing element of the sanding pad.
 43. The sanding machine of claim 42,wherein the counter-sealing element has an elastic ring body made of anelastic material.
 44. The sanding machine of claim 43, wherein at leastone contact body provided for grinding contact on the sealing elementand made of a material that is harder than the elastic material, isembedded in the ring body.
 45. The sanding machine of claim 42, furthercomprising it has an eccentric bearing device for eccentrically drivingthe sanding pad.